Window covering



FIG. 1 is a perspective view of a window covering showing my new design;

FIG. 2 is a top plan view of the design of FIG. 1;

FIG. 3 is a front elevation view of the design of FIG. 1;

FIG. 4 is a bottom plan view;

FIG. 5 is a right side elevation view of the design of FIG. 1;

FIG. 6 is a rear elevation view of the design of FIG. 1; and,

FIG. 7 is a left side elevation view of the design of FIG. 1.

CLAIM The ornamental design for a window covering, as shown.